2.0 The cell Flashcards
cell theory (3)
All organisms are composed of one or more cells
The cell is the basic structural and functional unit of all living organisms
Cell arise only from the division of preexisting cells
Nucleic acid, DNA and RNA (2)
carry hereditary information and direct the manufacture of cellular molecules.
Where do cells get energy to carry out their activities? (2)
- chemical molecules
- light as energy source
how do cells respond to changes in their external environment
alter their internal reactions
all forms of life can be divided into three domains
Bacteria, Archea and Eukarya
Each cell is functionally independent organisms capable of_______. (unicellular organisms) however cells in multicellular organisms
carrying out all activities necessary for living
are potentially capable of surviving by themselves if placed in a chemical medium that can sustain them.
If cells are broken open, (3)
The property of life is lost
They are unable to grow, reproduce or respond to outside stimuli in a coordinated potentially independent fashion.
Why are cells so small？(2)
SA to volume ratio of a cell changes as it gets bigger
Doubling the diameter of a cell increases its volume by eight times but increases its surface area by only four times
Significance of the Volume:SA relationship
Volume of the cell determines the amount of chemical activity that can take place within it. SA determines the amount of substances that can be exchanged between inside and outside environment.
Difference between light microscope and electron microscope.
light uses light to illuminate specimen while electron use electron
plama membranę (2)
a bilayer made of lips with embedded protein molecules
(regulates what goes and out)
Lipid bilayer
a hydrophobic barrier to the passage of water soluble substances
transport protein
a protein embedded in the cell membrane that forms a channel allowing selected polar molecules and ions to pass across the membrane.
hereditary info is organized in the forms of ____ in the cell which are
genes
segments of DNA that code for individual proteins
cytoplasm (2)
all parts of the cell between the plasma membrane and the central region
contains the organelles, the cytosol and cytoskeleton
organelles (2)
small organized structures important for cell function
the nucleus or other specialized internal structures
cytosol
aqueous water solution containing ions and various organic molecules
organic
molecules based on carbon
cytoskeleton
a protein based framework of filaments structures that among other things help maintain proper cell shape and plays a key role in cell division and chromosome segregation.
archaeans are almost as _____ from____ as you are.
different
bacteria
prokaryotic
lacking a nucleus
nucleiod (3)
present in bacteria and archaea
the DNA containing central region of the cell
has no boundary membrane separating it from the cytoplasm
nucleus
in eukaryotes
Store DNA contained within a membrane bound compartment
glycocalyx (3)
an external layer that coats the cell wall
helps protect prokaryotic cell from physical damage and desiccation(dehydration). Allow them to also attach to a surface or other cells
a polysaccharide
when glycocalyx is diffuse and loosely associated with the cell:
- a slime layer
when glycocalyx is gelatinous and firmly attached to the cell: (2)
capsule
an external layer of sticky or slimy polysaccharides coating the cell wall
Flagella
long threadlike protein fibres which extends from the cell surface.
prokaryotic cytoskeleton play important roles in (3)
in cell division, creating and maintaining the proper shape of the cell
for certain bacteria: determining the polarity of the cells
Bacteria flagellum how they move
helically shaped, rotates in a socket in the plasma mirage and cell wall to push through a liquid medium
pili
hairlike shaft of protein extending from cell wall
attach the cell to surfaces or other cells
only in bacteria and archaea
cell (2)
the basic structural and functional unit of all living organisms
carry out the essential processes of life.
in almost all prokaryotic cells, the plasma membrane is surrounded by a ___________, _____
rigid external layer of material
the cell wall
The cell wall
provides rigidity to prokaryotic cells and with the capsule, protects the cell
Eukaryotes are divided into 4 groups:
protists
fungi
plants
animals
the cells of all eukaryotes have a membrane bound compartment called the
nucleus
what isn’t in prokaryotic cells?
system of membranous organelles
cell fractionation
isolating specific organelles from the rest of the cell
some of the protein form channels through the plasma membrane that transport substances into and out of the cell. other protein in the plasma membrane _______________
act as receptors. They recognize and bind specific signal molecules in the cellular environment and trigger internal responses
A supportive cell wall surrounds (2)
the plasma membrane of fungal, plant and many protist cell
Extracellular structure
In general eukaryotic ribosomes are
larger then bacteria and archaea ribosomes. They contain four types of rRNA molecules and more then 80 proteins
in prokaryotes where are the ribosomes?
Roam freely in the cytoplasm
in eukaryotic where are the ribosomes?
roam free or on er
ribosomes are made up of
and made in
rRNA and proteins
the nucleolus and released to the cell
proteins made on free ribosomes in the cytosol may….
remain in the cytosol or pass through the nuclear pores into the nucleus or become parts of mitochondria, chloroplast , or other cytoplasmic structures
proteins that enter the nucleus become part of chromatin or line the nuclear envelope or remain in solution in the nucleoplasm
the proteins made on ribosomes attached to the ER
follow a special path to other organelles within the cell
mitochondria
membrane bound organelles in which cellular respiration occurs
cellular respiration
the process where energy rich molecules such as sugars fats and other fuels are broken down to water and co2 by mitochondria reactions with the release of energy. Much of the dingy released is captured in ATP
Mitochondria requires____ for cellular respiration
oxygen
Mitochondria requires____ for cellular respiration
oxygen
The outer mitochondria membrane
Is smooth and covers the outside of the organelle
The inner mitochondria membrane
expanded by folds called cristae
Where does the ATP generating reactions of mitochondria occur?
In the cristae and matrix
are chloroplast in eukaryotes
algal protist
are cell walls in eukaryotes
algal protist and fungi
chloroplast are family of
plastids
all plastids
contain DNA genome and molecular machinery for gene expression and the synthesis of proteins on ribosomes
some of the proteins within plastids are encoded by their genome other are encoded by nuclear genes and are imported into the organelles
grana
thylakoids stacked one onto of another
thylakoid
flattened closed sacs
contain chlorophyll that absorb light energy and convert it to chemical energy in photosynthesis
stroma
uses enzyme to make carbohydrates and other complex organic molecules from the chemical energy from photosynthesis and water, co2 and other simple inorganic precursors
